2-ethylhexyl 2-([1,1'-biphenyl]-4-ylcarbonyl)benzoate

Hydrolysis

Link to relevant study record(s)

Reference

Endpoint:

hydrolysis

Type of information:

experimental study

Adequacy of study:

key study

Study period:

02 OCtober 2020 to 15 July 2021

Reliability:

1 (reliable without restriction)

Qualifier:

according to guideline

Guideline:

EPA OPPTS 835.2120 (Hydrolysis of Parent and Degradates as a Function of pH at 25°C)

Version / remarks:

October 2008

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method C.7 (Degradation: Abiotic Degradation: Hydrolysis as a Function of pH)

Version / remarks:

March 04, 2016

Deviations:

no

Qualifier:

according to guideline

Guideline:

OECD Guideline 111 (Hydrolysis as a Function of pH)

Version / remarks:

April 13, 2004

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Specific details on test material used for the study:

Physical Description: Colourless to pale yellow liquid (determined by Charles River Den Bosch)
Purity/Composition: 96.69%
Storage Conditions: At room temperature
Purity/Composition correction factor: No correction factor required
Test item handling: No specific handling conditions required
Chemical name : 2-Ethylhexyl 2-([1,1'-biphenyl]-4-ylcarbonyl)benzoate
CAS number: 75005-95-7
EC Number: 278-051-5
Molecular formula: C28H30O3
Molecular weight: 414.22

Analytical monitoring:

yes

Details on sampling:

Not reported.

Buffers:

- pH: 4, 7 and 9
- Type and final molarity of buffer: Acetate buffer pH 4, 0.01 M, Phosphate buffer pH 7, 0.01 M, Borate buffer pH 9, 0.01 M.
- Composition of buffer: pH 4: Solution of 16.7% 0.01 M sodium acetate in water and 83.3% 0.01 M acetic acid in water., pH 7: Solution of 0.01 M potassium di-hydrogen phosphate in water adjusted to pH 7 using 1N sodium hydroxide. Buffer contained 0.0009% (w/v) sodium azide.Buffer contained 0.0009% (w/v) sodium azide, pH 9: Solution of 0.01 M boric acid in water and 0.01 M potassium chloride in water adjusted to pH 9 using 1N sodium hydroxide. Buffer contained 0.0009% (w/v) sodium azide.

Details on test conditions:

TEST SYSTEM
- Type, material and volume of test flasks, other equipment used: not reported
- Sterilisation method: not reported
- Lighting: test item placed in the dark.
- Measures taken to avoid photolytic effects: test item placed in the dark.
- Measures to exclude oxygen: To exclude oxygen, nitrogen gas was purged through the solution for 5 minutes.
- Details on test procedure for unstable compounds: not reported
- Details of traps for volatile, if any: not reported
- If no traps were used, is the test system closed/open: not reported
- Is there any indication of the test material adsorbing to the walls of the test apparatus?
TEST MEDIUM
- Volume used/treatment: 6 mL
- Kind and purity of water: buffer solutions
- Preparation of test medium: not reported
- Renewal of test solution: not reported
- Identity and concentration of co-solvent: acetonitrile
OTHER TEST CONDITIONS
- Adjustment of pH: not reported
- Dissolved oxygen: not reported

Duration:

5 d

pH:

9

Temp.:

19.9 °C

Initial conc. measured:

17.3 µg/L

Remarks:

Experiment repeated at 30 °C and 50 °C.

Duration:

5 d

pH:

7

Temp.:

20 °C

Initial conc. measured:

17.2 µg/L

Remarks:

Experiment repeated at 30 °C and 50 °C.

Duration:

5 d

pH:

4

Temp.:

20 °C

Initial conc. measured:

16.2 µg/L

Remarks:

Experiment repeated at 30 °C and 50.1 °C.

Number of replicates:

2

Positive controls:

not specified

Negative controls:

yes

Statistical methods:

Quantitative analysis was performed using Acquity UPLC system (Waters, Milford, MA, USA).

Preliminary study:

The buffer solutions were filter-sterilised through a 0.2 µm FP 30/0.2 CA-S filter (Whatman, Dassel, Germany) and transferred into a sterile vessel. To exclude oxygen, nitrogen gas was purged through the solution for 5 minutes. The test item was spiked to the solutions at a target concentration of 0.02 mg/L using a spiking solution in acetonitrile. For each sampling time, duplicate sterile vessels under vacuum were filled with 6 mL test solution and placed in the dark in a temperature controlled environment at 49.9°C ± 0.2°C.

The spiking volume was < 1% of the sample volume. Nominal concentrations were not corrected for the spiking volume.

The concentration of the test item in the test samples was determined immediately after preparation (t=0) and after 2.4 hours and 5 days.

Analysis was performed on subsamples of 250 µL. The samples were diluted in a 1:3 (v:v) ratio with acetonitrile and analyzed. The blank buffer solutions were diluted in a 1:3 (v:v) ratio with acetonitrile and analyzed.

Blank buffer solutions containing a similar content of blank spiking solution were treated similarly as the test samples and analyzed at t=0.

The pH of each of the test solutions (except for the blanks) was determined at each sampling time.

Transformation products:

not measured

% Recovery:

79

pH:

9

Temp.:

50 °C

Duration:

5 d

% Recovery:

78

pH:

9

Temp.:

30 °C

Duration:

5 d

% Recovery:

77

pH:

9

Temp.:

20 °C

Duration:

5 d

% Recovery:

70

pH:

7

Temp.:

50 °C

Duration:

5 d

% Recovery:

84

pH:

7

Temp.:

30 °C

Duration:

5 d

% Recovery:

83

pH:

7

Temp.:

20 °C

Duration:

5 d

% Recovery:

48

pH:

4

Temp.:

50 °C

Duration:

5 d

% Recovery:

63

pH:

4

Temp.:

30 °C

Duration:

5 d

% Recovery:

70

pH:

4

Temp.:

20 °C

Duration:

5 d

pH:

9

Temp.:

20 °C

DT50:

5.4 h

pH:

7

Temp.:

20 °C

DT50:

5 h

pH:

4

Temp.:

20 °C

DT50:

11 h

Information	Guideline(s)	Result	Comment
Hydrolysis at pH 4	EC C.7 OECD 111 OPPTS 835.2120	t½ = 11 hours at 20°C t½ = 5.1 hours at 25°C t½ = 2.2 hours at 30°C t½ = 0.53 hours at 50°C
Hydrolysis at pH 7	EC C.7 OECD 111 OPPTS 835.2120	t½ = 5.0 hours at 20°C t½ = 3.1 hours at 25°C t½ = 1.9 hours at 30°C t½ = 0.39 hours at 50°C
Hydrolysis at pH 9	EC C.7 OECD 111 OPPTS 835.2120	t½ = 5.4 hours at 20°C t½ = 3.5 hours at 25°C t½ = 2.4 hours at 30°C t½ = 0.35 hours at 50°C

 

Graphs appended to "attached documents".

Validity criteria fulfilled:

yes

Conclusions:

The hydrolysis of the test item as a function of pH was calculated.

Executive summary:

The objective of this study was to determine physico-chemical properties for the test item. The rate of hydrolysis of the test item as a function of pH was determined at pH values normally found in the environment (pH 4-9).

Description of key information

Study conducted to recognised testing guidelines with GLP certification.

Key value for chemical safety assessment

Half-life for hydrolysis:

11 h

at the temperature of:

20 °C